Prevent Potting Soil Fires Have you taken proper precautions with planter pots in and around your home or business to keep your family and property safe? Many potting soil mixes on the market today contain as much organic material as inorganic material. Potting soil can be made of shredded bark, wood and/or peat moss with minimal amounts of what we call real soil or dirt. Styrofoam pellets, perlite and vermiculite are some of the other items that are often added to the soil mixture for aeration and water retention. In addition, many mixtures also include different types of fertilizers. Some fertilizers are oxidizers which will make any fire that starts, grow at an even faster rate. Potting soil mixtures are shipped moist and in plastic bags from the manufacturer. Most people use potting soil in their planters in the spring and then forget about them once fall arrives. Bacterial decomposition then begins to occur within the mix which creates heat. This same decomposition is what makes compost piles and bales of hay heat up. This principle, which is called spontaneous combustion, is found more often in humid climates where water acts as a catalyst. However, these types of fires can also occur here in our dry Colorado climate. Fires can start when old potting soil is used as an ashtray. You may think you are putting your cigarette out into “dirt”, when in fact you are creating an opportunity for a fire to ignite. Precautions you can take to prevent potting soil fires: Do not use old planter pots that contain potting soil as an ashtray. Keep an ashtray in areas where someone might be smoking around potted plants. If you have dead plants in pots in and around your home, discard them properly by throwing them out in the trash or spreading the soil from the pots in your yard or garden. Keep your potted plants well watered and maintained. If you keep potting soil in your garage or on your deck, do not leave it near any combustible material.